JPS61201733A - Manufacture of shadow mask - Google Patents

Abstract

PURPOSE:To manufacture shadow mask having good press formability and superior resistances for buckling and resonance, by cold rolling iron base alloy having a specified compsn. composed mainly of Fe-Ni-Cr finally by high draft. CONSTITUTION:Iron base alloy composed of <=0.10wt% C, <=0.30% Si, <=0.30% Al, 0.1-1.0% Mn, 30-45% Ni, 2.0-10.0% Cr, if necessary further 0.01-1.0% of >=1 kind among Ti, Zr, Mo, Nb, B, V, Be, and the balance Fe with inevitable impurities is cold rolled finally by >=20% draft, to obtain shadow mask material having good press formability, high stiffness and superior resistances for buckling and resonance. In said method, before the final cold rolling, the alloy is cold rolled by >=40% draft, or without said rolling, next, grain size is controlled to >=7.0 size number by annealing, thereby, press formability can be further improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shadow mask material used in a color television picture tube.

Its use in the milling industry has also been proposed.

When the color picture tube is operated, the total number of electron beams passing through the apertures of the shadow mask is less than 173, and the remaining electron beams impinge on the shadow mask, causing the shadow mask to sometimes reach temperatures as high as 80 degrees Celsius. heated. At this time, a decrease in color purity occurs due to thermal expansion, but Fe −
The use of a Ni-based amber alloy reduces this thermal expansion. However, it is difficult to say that this Fe--Ni-based amber alloy satisfies all the requirements as a shadow mask material.

First of all, the press moldability is poor.

In general, manufacturing a shadow mask from shadow mask material involves a process of perforation by etching, annealing to impart press formability, a process of press molding into a predetermined shape, and other blackening treatments. A problem arises in that the yield strength is not reduced sufficiently. As a result, springback occurs due to elasticity, causing slight deviations in shape, and local distortion remains, resulting in poor spherical formability. In the case of Fe-Ni-based amber alloy, 1000
Even if annealing is performed at a high temperature of ℃ or higher, 24 to 25 kg/
The yield strength decreases only up to about 2 mm, and it is difficult to compensate for the moldability even by changing the press conditions of the mold, etc. Experience has shown that in order to achieve industrially stable press molding and obtain a good shadow mask, a material with a yield strength of 20 kg/nu" or less is desired before press molding, and a material that satisfies this is desired. It was rare.

Another problem is weak hips. The weak stiffness is due to two factors: annealing at high temperatures to reduce yield strength, which results in coarse grains, and the fact that the Fe-Ni amber alloy has a low Young's modulus to begin with. . The problems caused by this weak back are resonance phenomena and buckling. Resonance is a phenomenon in which when a shadow mask is assembled into a color picture tube, the shadow mask itself resonates due to external vibrations such as the sound of a speaker, and as a result, the delicate position of the hole in the shadow mask and the electron beam The relationship is misaligned and leads to a decrease in color purity.

A material with a low Young's modulus, that is, a weak material, resonates at a low frequency, or in other words, has poor resonance resistance. Buckling is a problem especially when the shadow mask is large, and due to the weakness of the back, the strength of the shadow mask after molding, especially in the center, is insufficient, resulting in a slight shock or shock when assembling the color picture tube. It is something that causes it to buckle due to stress.

These phenomena caused by weak hips can be prevented by increasing the thickness of the alloy plate used for the shadow mask, but
This would result in high costs, and the material would still be strong, that is, a material with a sufficiently high Young's modulus.

Experience has shown that a material with a Young's modulus of 17,000 kg/nu2 or more is desired.

In order to solve the above two problems at the same time, that is, poor press formability and weak stiffness, the Young's modulus must be 17,000 kg/m.
Use a material with a size of 2 m2 or more, and increase its yield strength to 20 m2 or more before press forming.
It is necessary to assemble a color picture tube using a shadow mask with kg / mu 2 or less, but in this case Fe
- It is necessary that the good low thermal expansion properties of the Ni-based amber alloy are not significantly impaired, and in practical terms 3.
It is necessary to maintain a thermal expansion coefficient of 0 to 1 (6.OX 10'/'C or less at 10°C).

The present inventors have found that these problems can be solved by using an iron-based alloy containing Fe-Ni-Cr as a main component as a shadow mask, and as a result, there is no color unevenness due to doming, and the characteristics and manufacturability of the shadow mask are improved. We are proposing an excellent shadow mask material.

We have discovered that this shadow mask material can also be manufactured with a proper manufacturing method to bring out more biased characteristics.

That is, the gist of the present invention is C0010% by weight.
Below, Si 0.30% or less, Al 0.30% or less, Mn 0.1-1.0%, Ni 30-45%,
A method for producing a shadow mask, characterized in that an iron-based alloy consisting of 2.0 to 0.0% Cr, the balance Fe and unavoidable impurities is subjected to final cold rolling at a reduction ratio of 20% or more, and a C0. 10% or less, Si 0.30% or less, Al 0.30% or less, Mn 0.1-1.0%.

Ni30-45%, Cr2. The iron-based alloy consisting of O~l0.0%, the balance Fe and unavoidable impurities is annealed to adjust the grain size to 7.0 or more in terms of grain size number, and then final cold rolled at a reduction rate of 20% or more. A method for producing a shadow mask with C0.102 in weight%
Below, Si 0.30% or less, Al 0.30% or less, Mn 0.1-1°, N130-45%, Cr2
．． After cold rolling an iron-based alloy consisting of 0-10.0%, the balance being Fe and unavoidable impurities at a reduction rate of 40% or more, the grain size is adjusted to a grain size number of 7.0 or more by annealing, followed by a reduction rate of 20%. % or more, and a method for producing a shadow mask characterized by final cold rolling at a C of 0.10% or more by weight.
Below, Si 0.30% or less, Al 0.30% or less,
Mn 0.1-1.0%, Ni 30-45%, Cr
2. O~10.0%, and Ti, Zr, Mo, N
Final cold rolling of an iron-based alloy sheet containing one or more of B, B, V, and Be in a total of 0.01 to 1.0% and the balance consisting of Fe and unavoidable impurities at a reduction rate of 20% or more. A method for producing a shadow mask, and a method for manufacturing a shadow mask, which is characterized in that the weight % TEC is 0.10% or less, Si is 0.30% or less,
AI 0.30% or less 1Mn 0.1-1.0%, Ni
30-45%, Cr 2.0-10.0%, and T
An iron-based alloy containing a total of 0.01 to 11 parts of one or more of i, Zr, Mo, Nb, B, V, and Be, with the remainder being Fe and unavoidable impurities, is annealed to adjust the crystal grain size. A method for producing a shadow mask characterized by adjusting the number to 7.0 or higher and then final cold rolling at a rolling reduction rate of 20% or higher, and a method for manufacturing a shadow mask, which is C0.10% by weight.
Below, Si 0.30% or less, AI 0.30% or less,
Mn 0.1-1.0%, N130-45%, Cr2
．． O~l0.0%, and Ti, Zr, Mo, Nb,
An iron-based alloy containing one or more of Il, V, and Be in a total of 0.01 to 1.0% and the remainder Fe and unavoidable impurities is cold rolled at a reduction rate of 40% or more and then annealed. A method for producing a shadow mask, characterized in that the grain size is adjusted to 7.0 or more in terms of grain size number, and then final cold rolling is performed at a reduction rate of 20% or more, and 3 after the final cold rolling.
The method of manufacturing a shadow mask includes performing heat treatment without recrystallization at a temperature of 00 to 1000°C.

Next, the reasons for the limitations of the present invention will be described.

C: When C exceeds 0.1 inch, the coefficient of thermal expansion increases.

Furthermore, the etching properties are inhibited due to the formation of iron carbides, making it unsuitable for shadow masks. Therefore, C should be 0.10% or less.

si; si is added for the purpose of deoxidizing, but 0.
If the content exceeds 30%, the hardness of the alloy increases and the yield strength after annealing is not sufficiently reduced. Therefore, Si should be 0.30% or less.

Al: Like Si, Al also has a deoxidizing purpose, and is 0.3
If the content exceeds 0%, a sufficiently low yield strength cannot be obtained after annealing. Therefore, Al should be 0.30% or less.

Mn; Mn is added for the purpose of deoxidizing and imparting hot workability, but if it is less than 0.1%, it has no effect, and if it is contained in excess of 1%, the coefficient of thermal expansion increases, and after annealing. The reduction in yield strength is not sufficient. Therefore, the component range is 0.1~
There will be 11 parts.

Ni: If Ni is less than 30%, the coefficient of thermal expansion becomes extremely high, leading to a decrease in the color purity of the color cathode ray tube. Even if the Ni content exceeds 45%, the coefficient of thermal expansion becomes high. Therefore, the component range is set at 30 to 45%.

Cr: The purpose of Cr is to increase Young's modulus, but if it is contained in an appropriate amount, the yield strength after annealing will also decrease. If the Cr content is less than 2.0%, the Young's modulus will not increase sufficiently, and the yield strength after annealing will not decrease enough. 10.0% Cr
If it is contained in a larger amount, the thermal expansion will increase significantly. Therefore, the component range is set to 2.0 to 10.0%.

Ti, Zr, Mo, Nb, B, V, Be;
These elements aim to increase Young's modulus and refine crystal grains, and improve resonance resistance and buckling resistance. The effect appears at 0.01% or more. Moreover, if the content exceeds 1.0% in total, the alloy will increase in hardness, and as a result, the yield strength after annealing will not be sufficiently reduced, press formability will deteriorate, and the coefficient of thermal expansion will also increase. Therefore, the component range is 0°01 ~
It shall be 1.0%.

As mentioned above, a shadow mask is generally made by etching and perforating a shadow mask material with a thickness of about 0.2 m or less, producing a flat mask, annealing it to give it press moldability, and then molding it into a spherical shape in the shape of a shadow mask. After that, it is manufactured after being subjected to blackening treatment, etc. In the manufacturing process of the shadow mask material, if the rolling reduction ratio in the final cold rolling is not sufficient, the 0.2% proof stress will not be sufficiently lowered under the same annealing conditions during the annealing that imparts press formability during the manufacturing process of the shadow mask.

This limit is a rolling reduction rate of 20%. Furthermore, a shadow mask using a shadow mask material that is finally cold-rolled at a rolling reduction of 20% or more has better buckling resistance and resonance resistance than a shadow mask material that has a smaller rolling reduction even after annealing under the same conditions.

In addition, the grain size is changed to 7 by annealing before final cold rolling.
．． By adjusting it to 0 or more, the 0.2% proof stress after annealing during the shadow mask manufacturing process is reduced and press moldability is improved. In addition, the finer crystal grains provide excellent homogeneity during etching and perforation. Furthermore, the rolling reduction rate is 40%
After the above cold rolling, the grain size is adjusted by annealing, and by final cold rolling, it is possible to reduce the negative effects of preferred orientation caused by hot rolling, etc., resulting in a shadow mask with excellent press formability. It becomes possible to manufacture Since the manufacturing method according to the present invention involves cold rolling at a higher rolling reduction than the usual manufacturing method for Fe--Ni-based invar alloys, there is a possibility that shape defects may occur after etching and perforation. Therefore, it is more desirable to perform a heat treatment that does not cause recrystallization after the final cold rolling. If the temperature at that time is lower than 300°C, it will not be effective, and if it exceeds 1000°C, it will be difficult to perform a heat treatment that does not actually cause recrystallization.The alloy used in the present invention contains 0 and S as impurities.

N is included, and any one of them is 0.
If the content exceeds 0.010%, N 0.0050%, and S 0.020%, etching perforation properties will be impaired.

Therefore, the content of the present invention is O0.010% or less, N0000
Naturally, it contains 50% or less and 50.020% or less.

Loss 11 The test materials were vacuum melted, cast, forged, hot rolled, pickled, cold rolled, annealed, final cold rolled, or the same up to hot rolling, and then pickled, cold rolled, and annealed. A cold-rolled plate having a thickness of 0.15 mm was obtained through the steps of cold rolling, annealing, and final cold rolling, and four types of components were used. In addition, some of the samples were subjected to heat treatment to prevent recrystallization after the final cold rolling.

The components of the sample materials are shown in Table 1.

Table 1 below shows the margin, and Table 2 shows the rolling reduction ratio during cold rolling and the grain size after annealing of the test materials. After degreasing the test material, apply the resist solution to a compress, dry it,
After developing and baking, a large number of holes were formed by etching and baking, followed by etching at 850°C for 10 minutes, 25% H2 - residual N2.
Annealing is performed in an atmosphere of
The resonance resistance was investigated. The survey results are also listed in Table 2.

As is clear from Table 2, the shadow mask materials manufactured according to the manufacturing conditions of Examples 1 to 14 of the present invention have excellent press formability, buckling resistance, and resonance resistance, and the manufacturing method brings out the characteristics of this alloy better. It is. In particular, Example 1 of the present invention in which cold rolling was performed at a reduction rate of 40% or more, the grain size was set to 7.0 or more in grain size number by annealing, and final cold rolling was performed at a reduction rate of 20% or more.
-10 obtained particularly excellent results. In addition, by applying heat treatment that does not cause recrystallization after the final cold rolling, press formability,
It was possible to manufacture a flat mask with a better shape without impairing buckling resistance and resonance resistance.

Comparative Example 15 has a low rolling reduction in the final cold rolling, so its press formability and resonance resistance are slightly inferior, and Comparative Examples 16 and 18 have slightly coarse grains due to annealing, and the rolling reduction in the final cold rolling is poor. Since the ratio is also low, press moldability and resonance resistance are slightly inferior. In Comparative Examples 17 and 19, the reduction rate in cold rolling was not sufficient and the crystal grains became coarse due to annealing, resulting in poor press formability, buckling resistance,
Poor resonance resistance.

Margin below

Claims (7)

[Claims] (1) By weight: C0.10% or less, Si0.30% or less, Al0.30% or less, Mn0.1-1.0%, Ni3
A method for manufacturing a shadow mask, which comprises final cold rolling an iron-based alloy consisting of 0 to 45% Cr, 2.0 to 10.0% Cr, the remainder Fe and unavoidable impurities at a reduction ratio of 20% or more. (2) C0.10% or less, Si 0.30% or less, Al 0.30% or less, Mn 0.1-1.0%, Ni3 in weight%
An iron-based alloy consisting of 0 to 45% Cr, 2.0 to 10.0% Cr, and the balance Fe and unavoidable impurities is annealed to adjust the grain size to 7.0 or more in terms of grain size number, followed by a reduction rate of 20%.
A method for producing a shadow mask, which comprises performing final cold rolling as described above. (3) C0.10% or less, Si 0.30% or less, Al 0.30% or less, Mn 0.1-1.0%, Ni3 in weight%
After cold rolling an iron-based alloy consisting of 0 to 45% Cr, 2.0 to 10.0% Cr, the balance Fe and unavoidable impurities at a reduction rate of 40% or more, the grain size is reduced to 7.0 or more in grain size number by annealing. A method for manufacturing a shadow mask, which comprises adjusting the shadow mask to a final cold rolling at a reduction rate of 20% or more. (4) C0.10% or less, Si 0.30% or less, Al 0.30% or less, Mn 0.1-1.0%, Ni3 in weight%
0-45%, Cr2.0-10.0%, and Ti, Zr
, Mo, Nb, B, V, and Be in a total of 0.01 to 1.0%, and the balance is Fe and unavoidable impurities. A method for producing a shadow mask, characterized by cold rolling. (5) C0.10% or less, Si 0.30% or less, Al 0.30% or less, Mn 0.1-1.0%, Ni3 in weight%
0-45%, Cr2.0-10.0%, and Ti, Zr
, Mo, Nb, B, V, Be in a total of 0.01 to 1.0% of one or more of them, and the balance is Fe and unavoidable impurities. A method for producing a shadow mask, which comprises adjusting the rolling stock to 7.0 or higher and then final cold rolling at a rolling reduction of 20% or higher. (6) C0.10% or less, Si 0.30% or less, Al 0.30% or less, Mn 0.1-1.0%, Ni3 in weight%
0-45%, Cr2.0-10.0%, and Ti, Zr
, Mo. After cold rolling an iron-based alloy consisting of a total of 0.01 to 1.0% of one or more of Nb, B, V, and Be and the remainder Fe and unavoidable impurities at a reduction rate of 40% or more, A method for producing a shadow mask, which comprises adjusting the grain size to 7.0 or more in terms of grain size number by annealing, and then final cold rolling at a reduction rate of 20% or more. (7) Claims (1) to (6) in which heat treatment without recrystallization is performed at a temperature of 300 to 1000°C after final cold rolling.
) The method for manufacturing the shadow mask described in .